Rear Air Suspension Issue - Troubleshooting

[tbro]

Hello folks,

Seems while I've had my 1993 LY 33' MH in the warehouse this winter that the rear end has developed a noticeable sag.

Anyone have any sources for troubleshooting?

I've checked the following:

Air compressor seems to work fine, dash gauge shows increase in pressure when running, otherwise it sits at 80psi.

Air bags appear to be in good shape showing no cracks and appear to be inflated though they don't raise the rear out of sag.

Air compressor is located under front hood on driver's side. Could this be an add-on system or did some units have that as a default install.

I cannot discover the make or model for my air suspension system, though my owners manual states the tag axle suspension is made by Henschen.

I assume that the suspension system bled off over time. Since the unit has been basically parked I didn't notice until recently how low the rear end had gotten. My bafflement is that it doesn't raise once the motorhome is started. The compressor does come on and then shuts off after awhile, though it seems to repeat the process more often than it should.

Any help appreciated but I was hoping to find some sort of troubleshooting guide.

[porourke]

We have a 93 LY with rear auto leveling suspension. If pressure is ok On the dash air guage but the coach still sets low first thing I would check is the two air leveling valves one on each side somewere on the undercariage. I cant tell you were because ours is single axel not tandum.
They take air from the accunuliator and eather fill, exhaust or stop air flow to raise, lower or hold the rear end. They work by an input shaft that moves up or down movement of the part of the coach that sets on top of the rear air bags. They may need adjustment, or as it was in my case they were both leaking air arround the input shaft to each valve. I could level it and come back the next day at the same time and had 40 to 45 Lbs. If you dont have a leak and try to adjust them to bring the coach back up to 10 to 10 1/2 " bear in mind that each valve has a 3 to 10 second delay built in so make small adjustments. If you have need of it I can send you a diagram of the airbag system, just PM me with an email add.

Good Luck